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我应该首先指出我对 Android 开发非常陌生，如果我的问题看起来很愚蠢，我很抱歉。我正在尝试在应用程序中查询我的 SQLite 数据库以动态创建活动内容。这是我的数据库助手文件中的查询

    public Cursor getWhereToEatActivity (int LocationId)
{
    Cursor cursor = myDataBase.rawQuery("SELECT Location.locationId as _id,Location.title,Location.desc, location.address, location.hours, location.website, location.phone FROM " +
            "TripWhereToEat JOIN Trip ON TripWhereToEat.tripId = Trip.tripId JOIN Location ON " +
            "Location.locationId = TripWhereToEat.locationId where TripWhereToEat.tripId = ?",
            new String[] {Integer.toString(LocationId)});

    cursor.moveToFirst();
    return cursor;
}

这是选择项目的位置：

 @Override
              public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {

                LocationListitem locationItem = (LocationListitem)lvItems.getItemAtPosition(position);

                int locationId = locationItem.getLocationId();

                // Pass the ID into the next activity
                Map<String, String> parms = new HashMap<String, String>();
                parms.put("locationId", Integer.toString(locationId));
                if (listType.equals("whattosee")) {
                    // switchActivity(WhatToSeeActivity.class, parms);
                }
                if (listType.equals("wheretostay")) {
                    // switchActivity(WhereToStayActivity.class, parms);
                }
                if (listType.equals("wheretoeat")) {
                    switchActivity(WhereToEatActivity.class, parms);
                }
              }
            });

这是活动切换到：

public class WhereToEatActivity extends FragmentActivityBase {

private int LocationId;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_where_to_eat);

    AndroidApplication app = (AndroidApplication)getApplication();

    DatabaseHelper myDbHelper = app.getDatabase(); // new DatabaseHelper(this);

    LocationId = Integer.valueOf(this.getParam("LocationId"));

    Cursor tripRecord = myDbHelper.getWhereToEatActivity(LocationId);

    tripRecord.moveToFirst();

    if (!tripRecord.isAfterLast()) {
        String name = tripRecord.getString(tripRecord.getColumnIndex("title"));
        String title = tripRecord.getString(tripRecord.getColumnIndex("desc"));
        String image = tripRecord.getString(tripRecord.getColumnIndex("image"));
        String address = tripRecord.getString(tripRecord.getColumnIndex("address"));

        ImageView mainImageView = (ImageView)findViewById(R.id.image);
        int resId = getResources().getIdentifier("com.integrativelogic.roadtrip:drawable/"+image, null, null); 
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(),resId);
        if (bitmap != null)
            mainImageView.setImageBitmap (bitmap);    

        TextView nameView = (TextView)findViewById(R.id.name);
        nameView.setText(name);

        TextView titleView = (TextView)findViewById(R.id.title);

        titleView.setText(Html.fromHtml(title));
        titleView.setMovementMethod(LinkMovementMethod.getInstance());

        TextView addressView = (TextView)findViewById(R.id.address);
        addressView.setText(address);
    }

    tripRecord.close();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}
}

这是我从 Logcat 得到的错误：

01-12 11:23:52.186: E/AndroidRuntime(15238): FATAL EXCEPTION: main
01-12 11:23:52.186: E/AndroidRuntime(15238): java.lang.RuntimeException: Unable to start  activity ComponentInfo{com.integrativelogic.roadtrip/com.integrativelogic.roadtrip.WhereToEatActivity}: java.lang.NumberFormatException: unable to parse '' as integer
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1821)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1842)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.app.ActivityThread.access$1500(ActivityThread.java:132)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1038)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.os.Looper.loop(Looper.java:150)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.app.ActivityThread.main(ActivityThread.java:4263)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at java.lang.reflect.Method.invokeNative(Native Method)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at java.lang.reflect.Method.invoke(Method.java:507)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at dalvik.system.NativeStart.main(Native Method)
01-12 11:23:52.186: E/AndroidRuntime(15238): Caused by: java.lang.NumberFormatException: unable to parse '' as integer
01-12 11:23:52.186: E/AndroidRuntime(15238):    at java.lang.Integer.parseInt(Integer.java:362)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at java.lang.Integer.parseInt(Integer.java:332)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at java.lang.Integer.valueOf(Integer.java:506)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at com.integrativelogic.roadtrip.WhereToEatActivity.onCreate(WhereToEatActivity.java:27)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1072)
01-12 11:23:52.186: E/AndroidRuntime(15238):    at     android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1785)
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2 回答 2

0

由于您是新手，所以当您的应用程序突然崩溃时，我将解释一下调试过程，如下所示：

第一部分是读取 LogCat 输出的最后几行：

引起：java.lang.NumberFormatException：无法将''解析为整数

所以我们知道尝试使空字符串成为整数是一个问题。您只能从包含数字的字符串创建整数。

您将看到日志中该行下方的几行

在 com.integrativelogic.roadtrip.WhereToEatActivity.onCreate(WhereToEatActivity.java:27)

那么我们知道它发生在您的 WhereToEatActivity 的第 27 行，我不会计算您在此处发布的内容的行数，但我假设是这一行

LocationId = Integer.valueOf(this.getParam("LocationId"));

所以我想可以安全地假设您遇到此错误的原因是因为没有参数“LocationId”或参数为空。

于 2013-01-12T16:50:05.320 回答
0

你的错误就在这里：

Caused by: java.lang.NumberFormatException: unable to parse '' as integer

我怀疑你这里有一个空的位置：

LocationId = Integer.valueOf(this.getParam("LocationId"));

如果此处引用了该行：

at com.integrativelogic.roadtrip.WhereToEatActivity.onCreate(WhereToEatActivity.java:27)
于 2013-01-12T16:51:55.630 回答